John cahxll



(No Model.)

J. CAHALL.

BoILBR.

No. 185,088L

Patented Oct. 25, 189.2.

UNTTE STATES PATENT OFFICE.

JOHN OAHALL, OF MANSFIELD, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO Il. E. OAI-IALL AND IV. H. OAHALL, OF SAME PLACE.

BOILER.

SPECIFICATION forming part of Letters Patent No. 485,088, dated October 25, 1892.

Application tiled August 3, 1892. Serial No. 442,032. (No model.)

following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in steam-boilers g and the objects of the invention are, rst, to provide for uniformly heating the water-tubes and super-heating the steamdrnm, and, secondly, to provide a boiler in which any sediment forming in the watertubes will fall into a mud-drum, from which it can be easily removed.

IfVth theserand other ends in view my invention consists in the combination, with an inclosing shell, of a mud-drum arranged centrally within the shell at the bottom thereof, a series of grates arranged within the shell around the mud-drum, a ,steam-drum arranged in the upper portion of the exterior shell and provided with a central vertical smoke-flue, which com municates with the combustion-chamber of the boiler and the smokestack thereof, and a series of concentric watertubes connecting the steam and mud drums, said tubes being inclined inwardly from their upper to their lower ends.

My invention further consists in the peculiar construction and arrangement of parts, as will be hereinafter more fully described and claimed.

In the accompanying drawings, Figure l is a vertical sectional view through a boiler constructed in accordance with my invention, and Fig. 2 is a horizontal sectional view on the line o; of Fig. l.

Like letters of reference denote corresponding parts in both the figures of the drawings, referring to which- A designates the exterior or inclosing shell of the boiler, which may be of anydesired size and preferably of greater width or diameter at its base than at its upper end, as shown.

Centrally within the shell A, at or near the bottom thereof, is arranged a mud-drum B, which drum is strengthened by means of suitable internal braces and is provided with a dome C or suitable manhole or aperture, through which the sediment accumulating 1n the mud-drum can be removed when desired. The mud-drum B is protected by asurrounding wall of lire-brick or other suitable material D, and between this protecting-wall D and the shell A around the drum B are situated a series of grates E.

A steam-drum F is situated within the shell A, near the upper end thereof, and this drum is connected with the mud-drum B by a serles of concentric water-tubes Gr. The tubes G are inclined inwardly from their upper to their lower ends to provide a cent-ral conlcal space H, which communicates at its upper widest end with a vertical central smoke-flue in the steam-drum, and said central flue communicates with the smoke-stack K of the boiler. The steam-drum is separated from the shell A throughout most of its height by an annular passage or chamber L, and said drum may be provided wit-h a dome M or any other suitable means of obtaining access to the steam-drum.

In using my improved boiler the heat and products of combustion arising from the fires on the grates E, in order to reach the central smoke-flue in the steam-drum and the stack of the boiler, must pass through and among the water-tubes G and uniformly heat the same. The steam in the steam-drum F is superheated by the smoke and products of combustion passing through the central vertical passage therein and by the heat passing around said drum through the annular passage or space L. By inclining the watertubes G in a reverse direction to the inclination of the exterior inclosing shell of the boiler a greater surface is exposed to the heat. The outer circle g of water-tubes G are of greater diameter than the other tubes, by means of which a free and proper circulation of water is maintained upwardly through the smaller tubes and downwardly through the larger tubes.

I am aware that changes in the form and proportion of parts and details of construction of the devices herein shown and described as an embodimentof my invention may be made without departing from the spirit or sacrific- IOO ing the advantages thereof, and I therefore reserve' the right to make such changes as fairly fall within the scope of the same.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a boiler, the combination of an exterior shell, a mud-drum arranged within and at the lower end of said shell, a series of grates arranged Within the shell around the muddrum, a steam-drum situated in the upper portion of the shell and provided with a central vertical smoke-flue, and a series of Watertubes connecting the mud and steam drums, substantially as described.

2. In a boiler, the combination of an exterior shell, a mud-drum arranged centrally within the shell at the bottom thereof, a series of grates arranged between the m ud-drum and exterior shell, a steam-drum arranged within the exterior shell and provided with a central vertical smoke-flue which communicates with the stack of the boiler, and a series of watertubes connecting the steam and mud drums, said tubes being inclined inwardly from their upper to their lower ends to form a central space which communicates with the smoketlue in the steam-drum, substantially as described.

3. In a'boiler, the combination of a tapering inclosing shell, a mud-drum arranged Within said shell near the bottom thereof, a series of grates arranged between the muddrum and exterior shell, a steam-drum arranged in the upper portion of the exterior shell and provided with a central Vertical smoke-flue which communicates With the stack of the boiler, and aseries of Water-tubes connecting the steam and mud drums, said tubes being inclined in a reverse direction to-the inclination of the exterior shell, substantially as described.

4. In a boiler, the combination of an exterior shell, a mud-drum arranged centrally within thevshell at the bottom thereof, aseries of grates arranged between the mud-drum and exterior shell, a steam-drum arranged Within the exterior shell and provided with a central vertical smoke-due, and a series of tubes ot' diierent diameters connecting the mud and steam drums, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN CAIIALL.

Witn esses:

WILLIAM Dovv, T. Y. MCCRAY. 

